Do It Yourself Rammed Earth
Frequently Asked Questions
Last updated Sunday, November 13, 2005

Q. What design do you plan to follow for the Rammed Earth home you are planning?

Our home is planned to be a 2400 sq ft, 2 story home with a balcony and covered porch surrounding the home. The external walls that will make up the thermal shell of the home will be 2 ft thick on the ground floor with 18" thick walls for the second floor. There will be no wiring or plumbing in the external walls. With a home surrounded by a shaded porch, balcony, and many trees, we hope the worst Dallas summer sun will never heat the rammed earth walls. Combined with a ventilated, reflective metal roof over insulation, we hope that annual air-conditioning needs will be greatly reduced if not totally eliminated.

Q. Why is Rammed Earth so rare in Dallas and the rest of the US?

There are multiple reasons that are the same throughout most of the US:

1. Stick construction (wood framing) is the norm due to a perceived abundance of lumber made possible by government subsidies and environmentally degrading forest management practices which unrealistically lower lumber prices.  These facts are combined with no significant US cultural tradition of building with earth.

2. While over 1/3 of the people on Earth live in earthen homes, most often such construction is associated with the third world and with poverty. Due to these perceptions, and a lack of public awareness of earth building technology, the public image of earthen homes is negative.  This results in low resale values for earthen homes and a lack of demand for such homes.

3. The truth of the urgency of the energy crisis, and the global consequences of pollution from most current energy sources, is only now, hopefully, beginning to be understood and admitted by a growing minority of the public.

4. While the value of rammed earth construction is clearly indicated in research, there is still relatively little research on this method. What research exists is only known by a small minority of the public.  More research is needed and it must be publicized.

5. While the materiel costs involved in a rammed earth (dirt) home are lower than the costs of materiel for normal construction, the extra labor costs involved leave the total final cost of such a home from 10% to 20% higher than the total cost of a normal wood frame home.

6. Due to the extra labor involved, the extra time involved, the lack of a product or service that can be patented and/or commercially restricted to one builder, and the need for public education, it has been very hard for any builder to gain the profits available through stick construction.

If anyone knows of rammed earth homes, or companies building such, near Dallas, please let us know. We have yet to find any company building with rammed earth located any closer to Dallas than Austin.

Q. What would you do differently with a rammed home in Dallas?

The answer is shade.  In Arizona and the areas of the southwest where rammed earth is more popular most rammed earth homes do not have shaded walls due to lower night time temperatures.  In Dallas such shading will be needed to keep the walls as cool as possible. The thermal flywheel effect will suffer in Dallas from relatively hot nights during the long summer.  Often it never goes below the 70's for months at a time in Dallas.  Consequently we need to do all we can to keep the walls as cool as possible by shading them with a large ventilated roofing system covering a porch and balcony surrounding the home. On the south side of the home we will use the winter sun to help heat the home.

Q. What are the current costs anticipated for the home you are planning?

(Bill' Answer) We are working on an answer for this question and hope construction starts before the next two years are up.  Construction may take as long as 18 months. Following is a VERY crude, and I hope high, estimate of costs for a 2,400 square foot two story home with 24" thick ground floor walls and 18" thick second story walls:

1. $8,000 to $15,000 for the dirt, 300 tons of it, and for about 15 tons of Portland Cement ($140 per ton) for the earth mixture.

2. $15,000 to $30,000 for work related to foundation, utilities and plumbing work. Foundation will be stronger and thicker than that required for normal stick construction due to the 300+ tons of weight it will have on it.  There will be no plumbing or wiring in the rammed earth thermal shell. (It could be done but we have decided to avoid related issues.) Utilities will only come up through the foundation and into the interior walls.  Most interior walls will be frame so that future owners, 100 years from now, can change the interior home configuration as they want without having to deal with rammed earth walls.

3. $15,000 to $25,000 for the equipment needed for the rammed earth wall construction as well as materiel for forms and framing interior walls.

4. $20,000 -$40,000 for beams and roofing system.  Please note that this will involve a ventilated metal roof that is insulated and will provide coverage for about 2,000 square feet due to the balcony that goes all around three sides of the home and will be covered by this roof. The goal is to shade the walls for most of every summer day.

This is a large cost range, from $58,000 to $110,000.  It is only a very crude estimate, and includes us doing about 4000 hours of work on the home ourselves.  We have not yet gotten bids on everything.   We still have to deal with city zoning.  I have not included costs related to an architect which we will probably need to sign off on the work. We have a long way to go but are driven by the promise of a quiet, healthy, efficient, rammed earth home.

Q. Can you build a rammed earth home in an area with a lot of rain?

Please send any questions you may have to bbetzen@openadoption.org.  We will try to find the answers if we do not already know them.

11-10-05
Bill & Stephen Betzen
A Father and Son planning & construction team
Dallas, Texas
bbetzen@openadoption.org
sbetzen@faircoffee.com